package com.ctrip.framework.apollo.biz.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.orm.jpa.EntityManagerFactoryAccessor;
import org.springframework.orm.jpa.EntityManagerFactoryUtils;
import org.springframework.orm.jpa.EntityManagerHolder;
import org.springframework.stereotype.Component;
import org.springframework.transaction.support.TransactionSynchronizationManager;

/**
 * @author Jason Song(song_s@ctrip.com)
 */
@Component
public class EntityManagerUtil extends EntityManagerFactoryAccessor {
	private static final Logger logger = LoggerFactory.getLogger(EntityManagerUtil.class);

	/**
	 * close the entity manager. Use it with caution! This is only intended for use
	 * with async request, which Spring won't close the entity manager until the
	 * async request is finished.
	 */
	public void closeEntityManager() {
		// 获得EntityManagerHolder对象
		EntityManagerHolder emHolder = (EntityManagerHolder) TransactionSynchronizationManager.getResource(getEntityManagerFactory());
		if (emHolder == null) {
			return;
		}
		logger.debug("Closing JPA EntityManager in EntityManagerUtil");
		// 关闭EntityManager
		EntityManagerFactoryUtils.closeEntityManager(emHolder.getEntityManager());
	}

}
